First off I just want to say that for a first matte painting, it's a really nice one.
It's very nicely cleaned and I sorta like the overall mood. The main thing I see that you need to work on is the lightning. For example; the towers should at a max have 50% lightning on them than what they have now (decreasing from right to left). Also the half circle glass thingy to the left aswell as the statue shouldn't be that bright since they're behind buildings. They don't need to be entierly dark but they should have less light on them since they do not have direct light on them.

Once again, for being your first time matte painting this is really nice.
Keep on going.
I'm looking forward to start seeing more. :]